Closure device and methods for making and using them

ABSTRACT

A method for closing an opening in a wall of a body lumen wherein an elongate member is advanced into the body lumen and a distal portion of an obturator is positioned distally beyond the distal end of the elongate member within the body lumen and in which one or more expandable elements on the distal portion of the obturator are expanded. The obturator is then withdrawn until the expandable elements contact the wall of the body lumen and a clip having tines is advanced over the elongate member until the tines penetrate the wall of the body lumen. The tines and the expandable elements are offset from one another. The elongate member is withdrawn from the body lumen and the clip substantially closes the opening in the body lumen.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a division of application Ser. No. 10/081,726, filedFeb. 21, 2002, now U.S. Pat. No. 6,623,510, which application is acontinuation-in-part of application Ser. No. 09/732,178, filed Dec. 7,2000, now U.S. Pat. No. 6,719,777 for “Closure Device and Methods forMaking and Using Them,” the disclosures of which are expresslyincorporated by reference herein.

FIELD OF THE INVENTION

The present invention relates generally to apparatus and methods forengaging tissue and/or closing openings through tissue, and moreparticularly to devices for closing a puncture in a blood vessel orother body lumen formed during a diagnostic or therapeutic procedure,and to methods for making and using such devices.

BACKGROUND

Catheterization and interventional procedures, such as angioplasty orstenting, generally are performed by inserting a hollow needle through apatient's skin and intervening tissue into the vascular system. A guidewire may then be passed through the needle lumen into the patient'sblood vessel accessed by the needle. The needle may be removed, and anintroducer sheath may be advanced over the guide wire into the vessel,e.g., in conjunction with or subsequent to a dilator. A catheter orother device may then be advanced through a lumen of the introducersheath and over the guide wire into a position for performing a medicalprocedure. Thus, the introducer sheath may facilitate introducingvarious devices into the vessel, while minimizing trauma to the vesselwall and/or minimizing blood loss during a procedure.

Upon completing the procedure, the devices and introducer sheath may beremoved, leaving a puncture site in the vessel wall. External pressuremay be applied to the puncture site until clotting and wound sealingoccur. This procedure, however, may be time consuming and expensive,requiring as much as an hour of a physician's or nurse's time. It isalso uncomfortable for the patient, and requires that the patient remainimmobilized in the operating room, catheter lab, or holding area. Inaddition, a risk of hematoma exists from bleeding before hemostasisoccurs.

Various apparatus have been suggested for percutaneously sealing avascular puncture by occluding the puncture site. For example, U.S. Pat.Nos. 5,192,302 and 5,222,974, issued to Kensey et al., describe the useof a biodegradable plug that may be delivered through an introducersheath into a puncture site. When deployed, the plug may seal the vesseland provide hemostasis. Such devices, however, may be difficult toposition properly with respect to the vessel, which may be particularlysignificant since it is generally undesirable to expose the plugmaterial, e.g., collagen, within the bloodstream, where it may floatdownstream and risk causing an embolism.

Another technique has been suggested that involves percutaneouslysuturing the puncture site, such as that disclosed in U.S. Pat. No.5,304,184, issued to Hathaway et al. Percutaneous suturing devices,however, may require significant skill by the user, and may bemechanically complex and expensive to manufacture.

U.S. Pat. No. 5,478,354, issued to Tovey et al., discloses a surgicalfastener including an annular base having legs that, in a relaxed state,extend in a direction substantially perpendicular to a plane defined bythe base and slightly inwards toward one another. During use, thefastener is fit around the outside of a cannula, thereby deflecting thelegs outward. The cannula is placed in an incision, and the fastener isslid along the cannula until the legs pierce into skin tissue. When thecannula is withdrawn, the legs move towards one another back to therelaxed state to close the incision.

U.S. Pat. Nos. 5,007,921 and 5,026,390, issued to Brown, disclosestaples that may be used to close a wound or incision. In oneembodiment, an “S” shaped staple is disclosed that includes barbs thatmay be engaged into tissue on either side of the wound. In anotherembodiment, a ring-shaped staple is disclosed that includes barbs thatproject from the ring. Sides of the ring may be squeezed to separate thebarbs further, and the barbs may be engaged into tissue on either sideof a wound. The sides may then be released, causing the barbs to returncloser together, and thereby pulling the tissue closed over the wound.These staples, however, have a large cross-sectional profile andtherefore may not be easy to deliver through a percutaneous site toclose an opening in a vessel wall.

Accordingly, devices for engaging tissue, e.g., to close a vascularpuncture site, would be considered useful.

SUMMARY OF THE INVENTION

The present invention is directed to devices and methods for engagingtissue, e.g., to connect tissue segments together or to close and/orseal openings through tissue, such as in a wall of a body lumen. Moreparticularly, the present invention is directed to vascular closuredevices or clips for closing a puncture in a wall of a blood vesselformed during a diagnostic or therapeutic procedure, and to methods formaking and using such devices.

In one aspect of the present invention, a device for engaging tissueincludes a generally annular-shaped body defining a plane and disposedabout a central axis extending substantially normal to the plane. Thebody may be movable from a substantially planar configuration lyinggenerally in the plane towards a transverse configuration extending outof the plane. The body may also include a plurality of looped elementsincluding alternating first and second curved regions that define aninner and outer periphery of the body, respectively, in the planarconfiguration. A plurality of tines or other tissue-engaging elementsmay extend from the first curved regions, and may be oriented towardsthe central axis in the planar configuration, and substantially parallelto the central axis in the transverse configuration. The device may bebiased towards the planar configuration, e.g., to bias the tines towardsthe central axis.

The looped elements of the device may generally define an endless zigzagpattern, e.g., a sinusoidal pattern, extending about the central axis.The looped elements may facilitating deforming the device between theplanar and transverse configurations, e.g., by distributing stressesthrough the device and minimizing localized stresses in the curvedregions. In addition, the looped elements may be expandable betweenexpanded and compressed states for increasing and reducing a peripheryof the body in the transverse orientation, respectively. The loopedelements may be biased towards one of the compressed and expandedstates.

Adjacent tines of the device may have a first curved region disposedbetween them. The first curved region between adjacent tines may includea substantially blunt element extending towards the central axis. Theblunt element may have a length shorter than lengths of the adjacenttines.

In addition or alternatively, the tines of the device may include firstand second primary tines, having a first length and a second length,respectively, which may be the same as or different than one another.The first and second primary tines may be disposed on opposing firstcurved regions, and may be oriented substantially towards each other inthe planar configuration. In the planar configuration, the first andsecond primary tines may at least partially overlap. The tines may alsoinclude one or more secondary tines having a length substantiallyshorter than the first and second lengths of the primary tines. Thesecondary tines may be disposed on either side of the first and secondprimary tines.

In another aspect of the present invention, a device for engaging tissueincludes a generally annular-shaped body defining a plane and disposedabout a central axis extending substantially normal to the plane. Thebody may be movable from a substantially planar configuration lyinggenerally in the plane towards a transverse configuration extending outof the plane. A first primary tine, having a first length, may extendfrom the body towards the central axis in the planar configuration, andmay be deflectable out of the plane when the body is moved towards thetransverse configuration. A second primary tine, having a second length,may extend from the body towards the first tine when the body is in theplanar configuration, and may be deflectable out of the plane when thebody is moved towards the transverse configuration. The lengths of thefirst and second primary tines may cause the primary tines to at leastpartially overlap in the planar configuration. The body may be biasedtowards the planar configuration to bias the tines generally towards thecentral axis.

The device may include a set of secondary tines having a length shorterthan the first and second lengths. The secondary tines may extend fromthe body towards the central axis in the planar configuration, and maybe deflectable out of the plane when the body is moved towards thetransverse configuration. In an exemplary embodiment, a secondary tinemay be disposed on either side of the first primary tine, and asecondary tine may be disposed on either side of the second primarytine.

Optionally, adjacent tines may have a first curved region disposedbetween them. The first curved region between adjacent tines may includea substantially blunt element extending towards the central axis. Theblunt element may have a length shorter than lengths of the adjacenttines.

Also, the device may include a plurality of looped elements disposedaround a periphery of the body. The looped elements may generally definean endless zigzag pattern extending about the central axis. The firstprimary tine and the second primary tine may extend from looped elementsdisposed opposite one another. The looped elements may be expandablebetween expanded and compressed states for increasing and reducing aperiphery of the body in the transverse orientation, respectively. Thelooped elements may be biased towards one of the compressed and expandedstates.

In another aspect of the present invention, a method is provided formanufacturing a clip from an elastic material, such as a sheet ofsuperelastic alloy, e.g., a nickel-titanium alloy (“Nitinol”). Thecomponents of the clip, e.g., a generally-annular body, optionallyincluding looped elements, and/or tines, may be formed by removingportions from the sheet. The portions may be removed, e.g., by lasercutting, chemical etching, photo chemical etching, stamping, electricaldischarge machining, and the like. The clip may be polished using one ormore processes, such as electro-polishing, chemical etching, tumbling,sandblasting, sanding, and the like, and/or heat-treated to provide adesired finish and/or desired mechanical properties. Optionally, thebody and tines may be coated with a therapeutic agent, e.g., a peptidecoating and/or one or more clotting factors.

In addition or alternatively, the clip may be disposed in a planarconfiguration, e.g., upon forming the clip from the sheet, and heattreated to form a clip biased to the planar configuration. For example,the clip may be formed from a shape memory material, e.g., Nitinol, thatmay substantially recover the planar configuration when heated to afirst predetermined temperature corresponding to an austenitic state,e.g., a temperature close to body temperature. The clip may be cooled toa second predetermined temperature corresponding to a martensitic state,e.g., a temperature at or below ambient temperature, and malleablymanipulated.

For example, the clip formed from the sheet may be deformed to atransverse configuration, such as that described above, e.g., by loadingthe clip onto a mandrel or directly onto a delivery device. If the clipincludes looped elements formed from the body, the looped elements maybe biased upon heat treatment towards an expanded state, but may bemalleably deformed to a compressed state upon cooling, e.g., tofacilitate loading onto the delivery device. Alternatively, the clip maybe formed from a superelastic material, e.g., Nitinol, such that theclip may be resiliently deformed to the transverse configuration and/orcompressed state, yet may automatically attempt to resume its planarconfiguration and/or expanded state upon release from external forces.

In still another aspect of the present invention, a method for closingan opening in a wall of a body lumen is provided. The distal end of anelongate member may be advanced through an opening in a patient's skin,along a passage through tissue, and into the body lumen. A distalportion of an obturator may be positioned distally beyond the distal endof the elongate member along the passage within the body lumen. One ormore expandable elements on the distal portion of the obturator may beexpanded transversely. The obturator may be withdrawn from the passageuntil the expandable elements contact the wall of the body lumen,thereby providing a tactile indication of a location of the wall of thebody lumen between the elongate member and the plurality of expandableelements of the obturator.

A clip may be advanced into the passage over the elongate member untiltines of the clip penetrate the wall of the body lumen, the tines andthe expandable elements on the obturator being angularly offset from oneanother such that the tines penetrate the wall at locations between theexpandable elements. The obturator may be collapsed, and the elongatemember and/or obturator may be withdrawn from the body lumen andpassage, leaving the clip to substantially close the opening in the wallof the body lumen. When the elongate member is withdrawn, the tines mayautomatically at least partially move towards a planar configuration tosubstantially close the opening.

The tines of the clip may include primary tines and secondary tines.Here, advancing the clip may include puncturing the wall of the bodylumen with the primary tines until tips of the primary tines enter thebody lumen, and puncturing the wall of the body lumen with the secondarytines. The primary tines and the secondary tines may puncture the wallswithout contacting the expandable elements of the obturator.

Other objects and features of the present invention will become apparentfrom consideration of the following description taken in conjunctionwith the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A is a top view of a first embodiment of a clip including aplurality of tines in a planar orientation, in accordance with thepresent invention.

FIGS. 1B and 1C are side views of the clip of FIG. 1A, with the tinesoriented substantially transversely from the planar orientation, incompressed and expanded states, respectively.

FIG. 2A is a top view of a second embodiment of a clip including aplurality of tines in a planar orientation, in accordance with thepresent invention.

FIGS. 2B and 2C are side views of the clip of FIG. 2A, with the tinesoriented substantially transversely from the planar orientation, incompressed and expanded states, respectively.

FIG. 3 is a top view of a third embodiment of a clip, in accordance withthe present invention.

FIG. 4 is a top view of an embodiment of a clip having radiopaquemarkers thereon.

FIG. 5 is a top view of an embodiment of a clip having pockets forholding radiopaque markers therein.

FIG. 6 is a top view of another embodiment of a clip including stopelements, in accordance with the present invention.

FIG. 7 is a top view of yet another embodiment of a clip including stopelements, in accordance with the present invention.

FIG. 8 is a top view of still another embodiment of a clip includingstop elements, in accordance with the present invention.

FIG. 9 is a side view of an apparatus, including an introducer sheathand an obturator, suitable for delivering a clip of the presentinvention.

FIGS. 10A–10D are cross-sectional views of a blood vessel, showing amethod for delivering a clip into a passage communicating with thevessel using the apparatus of FIG. 9.

FIG. 11A is a top view of the blood vessel of FIGS. 10A–10D, showing theorientation of the expandable elements of the obturator and openingsproduced by primary tines of the clip relative to an arteriotomy in thevessel.

FIG. 11B is a top view of the blood vessel of FIG. 11A, showing thearteriotomy being closed by the clip.

FIG. 12 is a top view of an embodiment of a clip having arcuate tines,in accordance with the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Turning now to the drawings, FIGS. 1A–1C show a first preferredembodiment of a closure device or clip 10 for closing an incision,puncture, or other passage through tissue, e.g., communicating with ablood vessel or other body lumen (not shown). The clip 10 includes abody 12, which may be generally annular in shape and surrounds a centralaxis 24, and a plurality of tines 16 extending from the body 12. As usedherein, an “annular-shaped body” includes any hollow body, e.g.,including one or more structures surrounding an opening, whether thebody is substantially flat or has a significant thickness or depth.Thus, although an annular-shaped body may be circular, it may includeother noncircular shapes as well, such as elliptical or other shapesthat are asymmetrical about a central axis.

The body 12 may include a plurality of looped or curved elements 30 thatare connected to one another to form the body 12. Each looped element 30may include an inner or first curved region 32 and an outer or secondcurved region 34. In a preferred embodiment, the first and second curvedregions 32, 34 are out of phase with one another and are connectedalternately to one another, thereby defining an endless sinusoidalpattern. Alternatively, other generally zigzag patterns may be providedthat repeat periodically, e.g., saw tooth or square tooth patterns (notshown), instead of a sinusoidal pattern, thereby defining inner andouter regions that alternate about the body 12. When the clip 10 is in asubstantially planar configuration, as shown in FIG. 1A, the firstcurved regions 32 may define an inner periphery 36 of the body 12 andthe clip 10, and the second curved regions 34 may define an outerperiphery 38.

The plurality of tines 16 may be biased to extend generally inwardly,e.g., towards one another and/or towards the central axis 24. The tines16 may be disposed on the first curved regions 32, and oriented towardthe central axis 24 when the clip 10 is in the planar configuration. Ina preferred embodiment, the tines 16 may be provided in pairs oppositefrom one another or provided otherwise symmetrically with respect to thecentral axis 24.

The tines 16 may include a variety of pointed tips, such as a bayonettip, and/or may include barbs (not shown) for penetrating or otherwiseengaging tissue. For example, to increase the penetration ability of theclip 10 and/or to lower the insertion force required to penetratetissue, each tine 16 may include a tapered edge (not shown) extendingtowards the tip along one side of the tine 16. Alternatively, each tine16 may be provided with a tapered edge on each side of the tine 16extending towards the tip.

Additionally, as shown in FIGS. 1A–1C, the tines 16 may be disposed onalternating first curved regions 32. Thus, at least one period of azigzag pattern may be disposed between adjacent tines 16, which mayenhance flexibility of the clip 10, as explained further below.

As shown in FIGS. 1B and 1C (where opposite ends 33 a, 33 b areconnected to one another), the body 12 and/or the tines 16 may bedeflected such that the tines 16 extend transversely with respect to theplane defined in the planar configuration, thereby defining a transverseconfiguration for the clip 10. Preferably, the tines 16 are orientedsubstantially parallel to the central axis 24 in the transverseconfiguration, as shown in FIG. 1B. In the transverse configuration, thebody 12 may have a generally annular shape defining a length, L₁, thatextends generally parallel to the central axis 24, and correspondsgenerally to an amplitude of the zigzag pattern. Preferably, the body 12is sufficiently flexible such that the clip 10 may assume a generallycircular or elliptical shape (not shown), e.g., conforming to anexterior surface of a delivery device (not shown) used to deliver theclip 10.

In a preferred embodiment, the tines 16 and/or body 12 are biased tomove from the transverse configuration towards the planar configurationof FIG. 1A. Thus, with the tines 16 in the transverse configuration, thetines 16 may penetrate and/or be engaged with tissue at a puncture site.When the clip 10 is released, the tines 16 may attempt to return towardsone another as the clip 10 moves towards the planar configuration,thereby drawing the engaged tissue together and substantially closingand/or sealing the puncture site, as explained further below.

The looped elements 30 may distribute stresses in the clip 10 as it isdeformed between the planar and transverse configurations, therebyminimizing localized stresses that may otherwise plastically deform,break, or otherwise damage the clip 10 during delivery. In addition,when the clip 10 is in the transverse configuration, the looped elements30 may be movable between a compressed state, such as that shown in FIG.1B, and an expanded state, such as that shown in FIG. 1C. Preferably,the looped elements 30 are biased towards the expanded state, but may becompressed to the compressed state, e.g., by constraining the clip 10.Alternatively, only a portion of the looped elements 30 may be biasedtowards the expanded state, e.g., the first curved regions 32, and/orthe looped elements 30 may be biased towards the compressed state.Furthermore, the looped elements 30 reduce the force required to beexerted on the clip 10 to transition the clip 10 from the planarconfiguration to the transverse configuration before loading onto adelivery device (not shown).

With the clip 10 in the transverse configuration, the looped elements 30may be circumferentially and/or radially compressed to the compressedstate until the clip 10 defines a first diameter or circumference 26 a,such as that shown in FIG. 1B. The clip 10 may be constrained in thecompressed state, e.g., by loading the clip 10 onto a carrier assemblyof a delivery device (not shown), as described further below. Whenreleased from the constraint, e.g., when deployed from the carrierassembly, the clip 10 may automatically expand towards the expandedstate, such as that shown in FIG. 1C, thereby defining a second diameteror circumference 26 b. Thus, the looped elements 30 may facilitatereducing the profile of the clip 10 during delivery, e.g., to facilitateintroducing the clip 10 through a smaller puncture or passage. Once theclip 10 is deployed entirely from the delivery device, the loopedelements 30 may resiliently expand as the clip 10 returns towards theplanar configuration, as explained further below.

To manufacture the clip 10 (or, similarly, any of the other clipsdescribed herein), the body 12 and the tines 16 may be integrally formedfrom a single sheet of material, e.g., a superelastic alloy, such as anickel-titanium alloy (“Nitinol”). Portions of the sheet may be removedusing conventional methods, such as laser cutting, chemical etching,photo chemical etching, stamping, using an electrical discharge machine(EDM), and the like, to form the clip. The tines 16 may be sharpened toa point, i.e., tips may be formed on the tines 16 using conventionalmethods, such as chemical etching, mechanical grinding, and the like.

The clip 10 may be polished to a desired finish using conventionalmethods, such as electro-polishing, chemical etching, tumbling,sandblasting, sanding, and the like. Polishing may perform variousfunctions depending on the method used to form the clip 10. For a clipformed by laser cutting or using an EDM, polishing may remove heataffected zones (HAZ) and/or burrs from the clip. For a clip formed byphoto chemical etching, polishing may create a smoother surface finish.For a clip formed by stamping, polishing may remove or reduce burrs fromthe bottom side of the clip, and/or may smooth the “roll” that mayresult on the topside of the clip from the stamping process.

In addition or alternatively, the clip 10 may be formed from a shapememory alloy, e.g., Nitinol, with the looped elements 30 formedinitially in the compressed state and/or the clip 10 in the planarconfiguration. With the clip 10 deformed to the transverseconfiguration, the clip 10 may be expanded, e.g., by applying a forceradially outwards against an inner surface of the clip 10, therebyexpanding the looped elements 30 to the expanded state. The loopedelements 30 may then be heat treated, e.g., by heating the clip 10 to anaustenitic state, to cause the looped elements 30 to “remember” theexpanded state, as is known to those skilled in the art. It may also benecessary to further heat treat the clip 10 further, e.g., with thetines in the planar configuration to cause the body 12 and/or tines 16to “remember” and be biased towards the planar configuration, as isknown to those skilled in the art. The clip 10 may then be cooled, e.g.,to a martensitic state, which may be at or close to ambient temperature,and manipulated, e.g., malleably deformed to the transverseconfiguration, for example, by loading the clip 10 onto a deliverydevice (not shown), as described below. Thus, if the clip 10 issubsequently heated to a predetermined temperature, e.g., at or belowbody temperature, the material may remember the planar configurationand/or expanded state and become biased towards them.

FIGS. 2A–2C show another preferred embodiment of a closure device orclip 110 that includes a generally annular-shaped body 112 defining aplane and disposed about a central axis 124 extending through the plane.The body 112 preferably includes a plurality of looped elements 130 thatare connected to one another to form the body 112, similar to theprevious embodiment. Each looped element 130 includes an inner or firstcurved region 132 and an outer or second curved region 134. Similar tothe previous embodiment, the first and second curved regions 132, 134may form an endless sinusoidal pattern or other generally zigzagpattern. When the clip 110 is in a substantially planar configuration,as shown in FIG. 2A, the first curved regions 132 may define an innerperiphery 136, and the second curved regions 134 may define an outerperiphery.

Unlike the previous embodiment, the clip 110 includes a plurality ofprimary tines 114 and a plurality of secondary tines 116. Each of theprimary and secondary tines 114, 116 may include a variety of knownpointed tips, similar to the previous embodiment.

Each of the primary tines 114 may have a length l₁, althoughalternatively each of the primary tines 114 may have a different lengththan one another. The primary tines 114 may be disposed in one or moreopposing pairs, e.g., on opposing first curved regions 132, and may beoriented towards and/or across the central axis 124 in the planarconfiguration. In the planar configuration, the lengths l₁ may besufficiently long such that the primary tines 114 at least partiallyoverlap one another, i.e., extend across the central axis 124 towards anopposing tine 114. Therefore, the tips of the primary tines 114 mayextend past the central axis 124 and/or the primary tines 114 in eachpair may lie substantially parallel to each other when the clip 110 isin the planar configuration.

Each of the secondary tines 116 may be disposed on a first or innercurved region 132, e.g., such that one or more secondary tines 116 maybe provided between opposing pairs of primary tines 114. Each of thesecondary tines 116 may have a length l₂ that is substantially less thanthe length l₁ of the primary tines 114.

Preferably, a secondary tine 116 is disposed on either side of eachprimary tine 114. For example, the clip 110 shown in FIGS. 2A–2C hasfirst and second primary tines 114, and each of the first and secondprimary tines 114 has a secondary tine 116 on either side of it. Thus,the clip 110 may have a total of two primary tines 114 and foursecondary tines 116. Optionally, the secondary tines 116 may be disposedsubstantially symmetrically about the central axis 124. The tines 114,116 may be provided on every other first curved regions 132. Forexample, a first curved region 132 having neither a primary tine 114 nora secondary tine 116 may separate each adjacent tine, e.g., between twoadjacent secondary tines 116, or between a secondary tine 116 and aprimary tine 114.

As shown in FIGS. 2B and 2C, the body 112 and/or the tines 114, 116 maybe deflected such that they extend transversely with respect to theplane defined in FIG. 2A. Preferably, the primary tines 114 andsecondary tines 116 are oriented substantially parallel to the centralaxis 124 to define a transverse configuration, as shown in FIG. 1B. Inthe transverse configuration, the body 112 has a generally annular shapedefining a length, LE₁, that extends generally parallel to the centralaxis 24, and corresponds generally to an amplitude of the sinusoidalpattern. Preferably, the body 112 is sufficiently flexible such that theclip 110 may assume a generally circular or elliptical shape (notshown), e.g., conforming to an exterior surface of a delivery device(not shown).

The tines 114, 116 may be biased towards one another and/or towards thecentral axis 124, i.e., due to the bias of the clip 110 towards theplanar configuration of FIG. 2A, similar to the previous embodiment.With the clip 110 in the transverse configuration, the clip 110 may bedelivered such that the primary tines 114 entirely penetrate the wall ofa blood vessel or other body lumen, while the secondary tines 116 onlypartially penetrate the wall due to their relative lengths, as explainedfurther below.

The looped elements 130 may be expandable between a compressed state, asshown in FIG. 2B, and an expanded state, as shown in FIG. 2C, similar tothe previous embodiment. Preferably, the looped elements 130 are biasedto the expanded state, but may be resiliently compressed to thecompressed state, e.g., by constraining the clip 110.

Turning to FIG. 3, an alternative embodiment of a clip 210 is shown thatincludes a body 112 including looped elements 130, and primary tines114, similar to the previous embodiment, but has no supplemental orsecondary tines 116. The reference numbers for elements of the clip 210are consistent with like elements used for the clip 110.

Any of the clips of the present invention may include one or moreradiopaque markers or other markers visible using external imaging, suchas fluoroscopy. For example, using the clip 110 of FIGS. 2A–2C as anexample, the entire clip 110 may be coated with radiopaque material,which may be a high density material such as gold, platinum,platinum/iridium, and the like.

Alternatively, the clip 110 may be partially coated with radiopaquematerial by using masking techniques. For example, the entire clip 110may first be coated with radiopaque material. The clip 110 may then bemasked at locations where the radiopaque coating is desired. Forexample, the looped elements 130 of the clip 110 may be left unmaskedduring this process if it is desired to leave the looped elements 130uncoated by radiopaque material. This may be desirable, e.g., to preventradiopaque material from adversely affecting the flexibility of thelooped elements 130. The clip 110 may then be treated to remove theradiopaque material from the unmasked areas, in this example, the loopedelements 130. The masking may then be removed using conventionalprocesses, leaving the rest of the clip 110 coated with radiopaquematerial.

Turning to FIG. 4, in another alternative, one or more discrete markers102 may be provided at predetermined locations on the clip 110. Forexample, high density or radiopaque material 102 may be crimped orotherwise secured onto opposing double looped or circular regions 130.In another embodiment, shown in FIG. 5, a plurality of pockets 104 maybe provided on the looped elements 130 into which high density plugs(not shown) may be bonded or otherwise secured. These various radiopaquemarkers may also be incorporated in any of the embodiments describedherein.

Turning to FIG. 6, another embodiment of a clip 310 is shown that,similar to clip 110, may include a plurality of looped elements 330 thatinterconnect to form a body 312. Each looped element 330 may have afirst or inner curved region 332 and a second or outer curved region334. Primary tines 314 may be disposed on opposing first curved regions332, which, optionally, may include a barb 302 thereon to enhanceengagement with tissue. Secondary tines 316 may be provided on firstcurved regions 332 on either side of each primary tine 314. In addition,a first curved region 332 without a tine 314, 316 may separate adjacenttines, as described above with regard to the previous embodiments.

The clip 310 also includes stop members 306 on one or more of the tines314, 316, e.g., adjacent the respective first curved region 332. Eachstop member 306 may be blunt-shaped, e.g., generally triangularly withan apex 307 of the stop member 306 extending from the first curvedregion 332, and the tine 314, 316 extending from a wide or blunt base307 of the stop member 306. During use, the blunt bases 307 may limitpenetration of the respective tines 314, 316 into tissue by reducing aneffective length of the respective tine 314, 316. For example, when thetines 314, 316 are driven into tissue, the tines 314, 316 may penetratethe tissue until the blunt bases 307 contact the tissue, whereupon thetines 314, 316 may be prevented from penetrating further into thetissue.

Turning to FIG. 7, another embodiment of a clip 410(i) is shown thatincludes a body 412, a plurality of tines 414, and a plurality of springelements 440(i) that interconnect between adjacent tines 414. The body412 includes outer curved regions 434 that extend between adjacent tines414, thereby defining an outer periphery for the clip 410(i). The clip410(i) may be moveable between a substantially planar configuration suchas that shown in FIG. 7, and a transverse configuration (not shown), andpreferably is biased towards the planar configuration, similar to theprevious embodiments.

In the embodiment shown, the spring elements 440(i) generally are hollowdiamond shaped elements, including curved inner regions 432(i) orientedtowards the central axis 424 of the body 412 when the clip 410(i) is inthe planar configuration. The spring elements 440(i) may serve multiplepurposes. First, the spring elements 440(i) may bias the clip 410(i),e.g., allowing the clip 410(i) to at least partially expand resiliently.For example, when the clip 410(i) is deflected into the transverseconfiguration (not shown), the spring elements 440(i) may allow thetines 414 to be moved away from the central axis 424 and/or one another.Thus, during deployment, the tines 414 may be deflected radiallyoutwardly or otherwise expanded to engage a larger area of tissue.

As the tines 414 are expanded, the spring elements 414(i) may deform tobecome wider (along a dimension extending generally between the adjacenttines 414) and shorter (along a dimension extending generally parallelto the tines 414). Once a force causing the tines 414 to expand isremoved, the spring elements 414(i) may resiliently try to returntowards their original shape, thereby pulling the tines 414 closertowards one another.

In addition, the curved inner regions 432(i) of the spring elements414(i) may provide stops limiting penetration of the tines 414 intotissue, similar to the stop members described above. For example, whenthe clip 410(i) is in the transverse configuration and the springelements 414(i) are expanded, the curved inner regions 432(i) may bebecome more oblique, possibly becoming generally linear. Thus, when thetines 414 are driven into tissue, the curved inner regions 432(i) maylimit penetration of the tines 414.

Finally, after the clip 410(i) is deployed, e.g., the tines 414 arepenetrated into tissue, the curved inner regions 432(i) may returntowards their original shape, and may pinch or otherwise engage tissuebetween the inner curved regions 432(i) and the adjacent tines 414.Thus, contracting the spring elements 440(i) may enhance the ability ofthe clip 410(i) to seal a puncture site, e.g., by pulling engaged tissueinwardly towards the central axis 424 of the clip 410(i).

Turning to FIG. 8, an alternative embodiment of a clip 410(ii) is shownthat is substantially similar to the clip 410(i) shown in FIG. 7, withthe exception of the shape of the spring elements 440(ii). Rather thandiamond shaped elements, the spring elements 440(ii) are looped elementsgenerally defining a circular shape.

Turning now to FIG. 12, another preferred embodiment of a clip 710 ofthe present invention is illustrated. Similar to the previousembodiments, the clip 710 includes a generally annular-shaped body 712that defines a plane. The body 712 is disposed about a central axis 724that extends through the plane. The body 712 preferably includes aplurality of outer curved elements 730 that extend between adjacenttines 716 and are connected to each other to form the body 712. When theclip 710 is in a substantially planar configuration, as shown in FIG.12, the curved elements 730 define an outer periphery 738 of the clip710.

The tines 716 are curved or arcuately shaped and include distal tips 715that extend toward the central axis 724 when the clip 710 is in thesubstantially planar configuration. Optionally, one or more of the tines716 may include barbs 717, similar to the previous embodiments.Preferably, the curve of the tines 716 are all in phase with one anothersuch that the tines 716 spiral about the central axis 724. This mayallow a length of the tines 716 to be maximized for a given diameter ofthe body 712.

For example, the tines 716 may have a length that is greater than aradius of the body 712 without the distal tips 715 of the tines 716touching one another. Thus, due to the arcuate shape of each tine 716,the tines 716 of clip 710 may be generally longer than the straighttines of the previous clips having comparable diameters. The tines 716may, therefore, penetrate deeper into tissue than the tines of the otherclips.

As with the previous embodiments, the body 712 and/or the tines 716 ofclip 710 may be deflected until the tines 716 extend transversely withrespect to the plane defined in the planar configuration, therebydefining a transverse configuration. In the transverse configuration,the tines 716 may be oriented substantially parallel to the central axis724. Additionally, as with the previous embodiments, the tines 716and/or body 712 may be biased to move from the transverse configurationtowards the planar configuration. The clip 710 may be delivered insubstantially the same manner as will be described with respect to otherclips of the present invention.

Any of the clips of the present invention may be coated with a substancethat enhances hemostasis and/or healing of a blood vessel, e.g., byincreasing a rate of regeneration of endothelium on the interior surfaceof the vessel, or by decreasing inflammatory response at the treatmentsite. In one embodiment, a suitable synthetic peptide coating may beapplied to a clip to attract endothelial cells to the surface. Anexemplary synthetic peptide coating may, for example, attach to the samecell binding sites as collagen. In another embodiment, a clip may becoated with a combination of clotting factors in order to promotehemostasis. For example, one side of the clip may be coated with FactorIII and an endopeptidase, such as PTA, to accelerate the intrinsicclotting pathway. On the opposite side of the clip, a combination of aprotein cofactor proaccelerin (Factor V) and an activated endopeptidase,such as serum prothrombin conversion accelerator (SPCA),cothromboplastin, and the like, may be applied to accelerate theextrinsic clotting pathway. The clips of the present invention may alsobe coated with any suitable hydrophilic polymer that swells in thepresence of bodily fluids in order to reduce, minimize, or stop bloodflow, thereby aiding the hemostasis process.

The clips of the present invention may be delivered using variousapparatus and methods. An exemplary apparatus 500 suitable fordelivering a clip of the present invention is shown in FIG. 9. Othersuitable apparatus that may be used to deliver a clip of the presentinvention are disclosed in co-pending U.S. application Ser. No.10/0821,723, filed on the same day as the present application andentitled “Apparatus and Methods for Delivering a Closure Device”, whichis assigned to the assignee of the present application. The disclosuresof this application and any references cited therein are expresslyincorporated by reference.

Generally, the apparatus 500 includes an introducer sheath 552, and ahousing or carrier assembly 554 slidably disposed on the sheath 552. Thesheath 552 includes a substantially flexible or semi-rigid tubular body558 including a lumen 560 extending between its proximal and distal ends562, 564. The distal end 564 has a size and shape configured tofacilitate insertion into a blood vessel, e.g., having a tapered tip forfacilitating substantially atraumatic introduction through the passageand at least partially into the vessel. The lumen 560 has a size forinserting one or more devices therethrough, such as a catheter,guidewire, and the like (not shown). The sheath 552 also preferablyincludes one or more seals (not shown), such as a hemostatic valve,within the lumen 560 at or near the proximal end 562 that provides afluid-tight seal, yet accommodates inserting one or more devices intothe lumen 560 without fluid passing proximally from the sheath 552.

Optionally, the sheath 552 may include a side port 566 that communicateswith the lumen 560, for example, to deliver fluids into the lumen 560.Alternatively, or in addition, the side port 566 may be used to providea “bleed back” indicator. An exemplary “bleed back” indicator andrelated methods of use are disclosed in co-pending application Ser. No.09/680,837, filed Oct. 6, 2000, entitled “Apparatus and Methods forPositioning a Vascular Sheath,” which is assigned to the assignee of thepresent application. The disclosure of this application and any otherreferences cited therein are fully incorporated by reference herein.

The apparatus 500 may also include a mechanical locator or obturator600, such as that disclosed in U.S. application Ser. No. 10/081,723,incorporated by referenced above, that may be part of an actuatorassembly (not shown) that is attachable to the proximal end of thesheath 552. Alternatively, the mechanical locator or obturator 600 maybe a separate device that is insertable into the lumen 560, e.g.,through the actuator assembly. Generally, the obturator 600 is anelongate member including a distal tip 614 and a distal portion 616. Thedistal tip 614 may be substantially soft and/or flexible such that thedistal tip 614 may substantially atraumatically enter the vessel 590(not shown, see FIGS. 10A–10D). The distal portion 616 generallyincludes one or more wings or other expandable elements 618 forproviding tactile feedback, as described further below.

The carrier assembly 554 is slidably disposed on an exterior of thesheath 552, and is configured for releasably carrying a clip 110 (shownin phantom), which may any of the clips described herein. The carrierassembly 554 may be substantially permanently attached to the sheath 552and/or may be actuated from the proximal end 562 of the sheath 552, forexample, by the actuator assembly (not shown), to advance the clip 110distally during deployment. Alternatively, the clip 110 may be carriedby an actuator assembly, as disclosed in co-pending U.S. applicationSer. No. 10/081,725, filed on the same day as the present applicationand entitled “Sheath Apparatus and Methods for Delivering a ClosureDevice,” which is assigned to the assignee of the present application.The disclosures of this application and any references cited therein areexpressly incorporated herein by reference.

Turning to FIGS. 10A–D, the apparatus 500 may be used to deliver theclip 110 to close and/or seal an incision, puncture, or other passage592 that extends from a patient's skin 594, through intervening tissue596, and into a wall 598 of a vessel 590 or other body lumen.Alternatively, the apparatus 500 may be used to deliver the clip 110 toengage tissue in other procedures, e.g., to connect tissue segmentstogether or otherwise to secure tissue structures with respect to oneanother. For example, the apparatus 500 and clip 110 may be used toattach an anastomosis during a bypass procedure. It will be appreciatedby those skilled in the art that the clip 110 and/or apparatus 500 maybe useful in a variety of procedures.

As shown in FIG. 10A, the sheath 552 may be inserted or otherwisepositioned within the vessel 590, i.e., through the passage 592. Thesheath 552 may be advanced over a guidewire or other rail (not shown)previously positioned through the passage 592 into the vessel 590 oradvanced in conjunction with a pointed stylet directly through tissueusing conventional procedures. Preferably, the vessel 590 is aperipheral vessel, such as a femoral, radial, or carotid artery,although other body lumens may be accessed using the sheath 552, as willbe appreciated by those skilled in the art.

The passage 592, and consequently the sheath 552, may be oriented at anangle “alpha” with respect to the vessel 590, thereby facilitatingintroducing devices through the lumen 560 of the sheath 552 into thevessel 590 with minimal risk of damage to the vessel 590. One or moredevices, such as a guide wire, a catheter, and the like (not shown), maybe inserted through the sheath 552 and advanced to a desired locationwithin the patient's body. For example, the devices may be used toperform a therapeutic or diagnostic procedure, such as angioplasty,atherectomy, stent implantation, and the like, within the patient'svasculature.

After the procedure is complete, any devices used during the proceduremay be removed from the sheath 552, and the obturator 600 may beinserted into the lumen 560. For example, the obturator 600 may be partof an actuator assembly (not shown), and may be advanced through thelumen when the actuator assembly is attached to the proximal end of thesheath 552. Alternatively, the actuator assembly and obturator 600 maybe coupled separately to the sheath 552.

When the obturator 600 is fully inserted within the sheath 552, thedistal portion 616 of the obturator 600 may extend beyond the distal end564 of the sheath 552. In an alternative embodiment, the obturator 600may be attached to an exterior surface (not shown) of the sheath 552,for example, along a track, e.g., including cooperating slots, grooves,and the like (not shown) in the sheath 552 and obturator 600.

Turning to FIG. 10B, the expandable elements 618 on the distal portionof the obturator 600 may then be directed to their expandedconfiguration, for example, by activating a switch on the proximal end(not shown) of the obturator 600. With the sheath 552 and obturator 600coupled to one another, the sheath 552 and obturator 600 may be moved inconjunction with one another.

As shown in FIG. 10C, the sheath 552 may be partially withdrawn from thevessel 590, until the expandable elements 618 contact the wall 598 ofthe vessel 590. Thus, the expandable elements 618 may provide a tactileindication of the position of the sheath 552 with respect to the wall598 of the vessel 590. In addition, the expandable elements 618 mayassist in “presenting” the wall 598 of the vessel 590, e.g., forreceiving the clip 110.

Generally, the clip 110 is carried by the carrier assembly 554 beforethe procedure. The clip 110 may be constrained in its transverseconfiguration on the carrier assembly 554, and the carrier assembly 554may be provided on or adjacent the proximal end of the sheath 552.Because the tines, which may include primary and secondary tines 114,116 may be biased towards one another, the tines 114, 116 may slidablycontact an inner surface (not shown) of the carrier assembly 554 or anouter surface of the sheath 552, thereby constraining the clip 110 inits transverse configuration.

Turning to FIG. 10D, with the sheath 552 properly positioned, thecarrier assembly 554 may then be actuated, for example, to advance thecarrier assembly 554 distally over the sheath 552 to deliver the clip110. Preferably, the carrier assembly 554 may only be advanced apredetermined fixed distance relative to the distal end of the sheath552, and consequently, the expandable elements 618 of the obturator 600,such that the clip 110 substantially engages the wall 598 of the bloodvessel 590. This predetermined distance may facilitate properlydeploying the clip 110 with respect to the wall 598 of the vessel 590,e.g., to prevent advancing the clip 110 too far, i.e., into the vessel590.

As the clip 110 is deployed from the carrier assembly 554, the clip 110may be expanded to an enlarged diameter. For example, a distal end ofthe carrier assembly 554 may include a ramped region (not shown) thatmay deflect the tines 114, 116, and/or the body of the clip 110 radiallyoutwardly. As the clip 110 is advanced over the ramped region, the tines114, 116 may be deflected radially outwardly as they are being driveninto the surrounding tissue, thereby engaging a larger region of tissuethan if the tines 114, 116 had been maintained substantially axially.

Alternatively, the clip 110 may include expandable looped elementsand/or spring elements (not shown), such as those described above, thatmay facilitate expanding the clip 110 as it is deployed from the carrierassembly 554 and/or the sheath 552. For example, the looped elements ofthe clip 110 may be compressed when the clip 110 is loaded into thecarrier assembly 554, e.g., thereby allowing a relatively smallerprofile carrier assembly 554 to be used. The clip 110 may automaticallyexpand upon deployment from the carrier assembly 554 to engage a largerregion of tissue surrounding the opening, such as an arteriotomy 591 inthe wall 598 of the vessel 590 (see FIG. 11A).

Once the clip 110 is deployed entirely or otherwise released from thesheath 552, the clip 110 may resiliently move towards its substantiallyplanar configuration, such as that shown in FIG. 11B.

During delivery of the clip 110, radiopaque markers (not shown) on theclip 110, the carrier assembly 554, and/or the expandable members 618may be monitored, e.g., using fluoroscopy, to facilitate observingand/or positioning the apparatus 500. Thus, a relative position of theclip 110 with respect to the expandable elements 618, and consequentlyto the wall 598 of the vessel 590, may be ascertained before the clip110 is deployed from the carrier assembly 554.

Turning to FIGS. 11A and 11B, in a preferred embodiment, the expandableelements 618 of the obturator 600 may be rotationally offset from theone or more tines 114 on the clip 110. For example, if the clip 110includes primary tines (such as those shown in FIGS. 2A and 3), theobturator 600 and clip 110 may have a predetermined relative angularorientation about the central axis 124. Preferably, the clip 110 isloaded onto the carrier assembly 554 in a predetermined angularorientation and the obturator 600 is receivable in the sheath 552 onlyin a predetermined angular orientation that is offset such that thetines 114, 116 are out of axial alignment with the expandable elements618, as shown in FIG. 11A.

This predetermined rotational orientation may substantially minimize thepossibility of the primary tines 114 contacting and/or damaging theexpandable elements 618. For example, with particular reference to FIG.11A, a preferred relative angular orientation of the clip 100 andobturator 600 is shown relative to an arteriotomy 591 in the wall 598 ofthe vessel 590. Here, the expandable elements 618 are oriented tocrisscross diagonally the arteriotomy 591 within the interior of thevessel 590. Generally, because of the natural structure of the tissue inthe wall of a vessel, an arteriotomy generally tends to adopt anelongate shape that extends transversely to the direction of flow (i.e.,across the circumference of the vessel wall).

The primary tines 114 are oriented such that the primary tines 114pierce the wall 598 of the vessel 590 on either side of the arteriotomy591, as shown. With the expandable elements 618 crisscrossingdiagonally, risk of contact with the primary tines 114 is substantiallyreduced. Thus, the primary tines 114 may be sufficiently long to extendentirely through the wall 598 of the vessel 590 while avoiding theexpandable elements 618.

The expandable elements 618 may then be collapsed and/or withdrawn intothe distal end 564 of the sheath 552. As the clip 110 is releasedentirely from the sheath 552, the primary tines 114 may partiallyoverlap, as shown in FIG. 11B, thereby pulling the arteriotomy 591closed, similar to a single-thread suture. For example, the expandableelements 618 may be automatically collapsed immediately before or afterthe clip 110 is deployed from the carrier assembly 554 or when thecarrier assembly 554 reaches its extreme distal position. Preferably,the distal portion 616 of the obturator 600 is collapsed and retractedinto the sheath 554 after the primary tines 114 have pierced the wall598 of the vessel 590, but before the clip 110 is entirely released fromthe sheath 552.

In addition, if the clip 110 includes secondary tines 116 (such as thoseshown in FIG. 2A), the secondary tines 116 may partially penetrate thewall 598 of the vessel 590 during deployment of the clip 110.Preferably, the lengths of the secondary tines 116 are relatively shortor stop members (not shown) may be provided that prevent the secondarytines 116 from piercing entirely through the wall 598. When the clip 110is released, the secondary tines 116 may pull the tissue inwardly,behaving somewhat similarly to a purse-string suture, to enhance closingthe arteriotomy 591.

Once the clip 110 is successfully deployed into the wall 598 of thevessel 590, e.g., on either side of an arteriotomy 591, the apparatus500 may be withdrawn from the passage 592. The entire apparatus 500 maybe removed in one step, or alternatively, the obturator 600 may first bewithdrawn from the sheath 552 before withdrawing the sheath 552, therebyleaving the clip 110 in place to close the arteriotomy 591 and/or sealthe passage 592. In addition, if desired, a sealant or other materialmay be introduced into the passage 592 in conjunction with or separatefrom delivery of the clip 110 to further seal the passage 592, as isknown to those skilled in the art.

While the invention is susceptible to various modifications, andalternative forms, specific examples thereof have been shown in thedrawings and are herein described in detail. It should be understood,however, that the invention is not to be limited to the particular formsor methods disclosed, but to the contrary, the invention is to cover allmodifications, equivalents and alternatives falling within the spiritand scope of the appended claims.

1. A method for closing an opening in a wall of a body lumen,comprising: advancing a distal end of an elongate member through apassage and into a body lumen; positioning an obturator distally beyondthe distal end of the elongate member along the passage within the bodylumen; expanding one or more expandable elements of the obturator;withdrawing the obturator from the passage until an expandable elementcontacts an inner wall of the body lumen, thereby providing a tactileindication of the inner wall of the body lumen; advancing a clip havingtines into the passage over the elongate member until the tines of theclip engage the wall of the body lumen; and withdrawing the elongatemember from the body lumen and passage, leaving the clip tosubstantially close the opening in the wall of the body lumen, and aplurality of the tines and the clip translating into a substantiallyplanar configuration.
 2. The method of claim 1, further comprisingproviding a carrier assembly on the elongate member, the carrierassembly carrying the clip.
 3. The method of claim 1, wherein the tinescomprise primary tines and secondary tines, and wherein advancing theclip comprises: puncturing the wall of the body lumen with the primarytines until tips of the primary tines enter the body lumen; and engagingthe wall of the body lumen with the secondary tines.
 4. The method ofclaim 3, wherein the secondary tines further include tissue stops. 5.The method of claim 2, wherein the passage is defined by a sheath. 6.The method of claim 1, wherein the clip is constructed of a superelasticmaterial.
 7. The method of claim 6, wherein the clip is nitinol.
 8. Themethod of claim 1, wherein the expandable elements of the obturatorretract simultaneously with the advancing of the clip.
 9. The method ofclaim 1, further comprising the step of expanding the clip prior toadvancing.